Printed and carriage control therefor

ABSTRACT

A teleprinter or the like wherein a typewheel is rotated around a helically grooved rod. The typewheel has an internal projection to ride in the groove. The rod is rotated at different speeds for carriage advance, stop and return. The typewheel is rotated continuously.

United States Patent [191 Taylor 1 1 Apr. 2, 1974 PRINTED AND CARRIAGECONTROL [561 References Cited THEREFOR UNITED STATES PATENTS lnventoriTerence Francis Edward Taylor, 2,774,8l6 l2/l956 Yost 197 49 x BurgessHill, England 3,630,335 12 1971 Chamncss 197 49 [73] Assignee:International Standard Electric Corp New York, NY PrimaryExaminer-Robert E. Pulfrey Assistant ExaminerR. T. Rader [22] Ffled'1972 Attorney, Agent, or FirmC. Cornell Remsen, Jr. [21] Appl. No.:295,153

' V [57] ABSTRACT [30] Foreign Application Priority t A teleprinter orthe like wherein a typewheel is re- Oct. 14, 1971 Great Britain 47836/71tated around a helically grooved rod. The typewheel has an internalprojection to ride in the groove. The [52] U.S. Cl. 197/49, 74/27 rod isrotated at different speeds for carriage advance, [51] InLCl B4lj 1/32stop and return, The typewheel is rotated continul ously.

Field of Search 197/49, 1, 18, 50;

2 Claims, 3 Drawing Figures I PRINTED AND CARRIAGE CONTROL THEREFORBACKGROUND OF THE INVENTION This invention relates to the printing art,and more particularly, to a teleprinter or the like and a carriagecontrol therefor.

In the past it has been difficult and expensive to maintainteleprinters.

SUMMARY OF THE INVENTION BRIEF DESCRIPTION OF THE DRAWINGS In thedrawings which are to be regarded as merely illustrative:

FIG. 1 is a top plan veiw of a traversing drive constructed inaccordance with the present invention; and

FIGS. 2 and 3 are enlarged views, partly in section, of the traversingdrive shown in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT sary, and a typewheel drivepinion Pinion 5' is fixed relative to typewheel 1 and meshes with pinion4'. The typewheel drive pinion 5 is supported on a rotatable cylindricalrod 6' having a helical groove 7 cut into its surface. A tooth in thebore of the typewheel drive pinion 5 (not visible in the figure) engagesin the groove, so that when there is relative rotary motion betweentypewheel drive pinion 5 and rod 6, the typewheel drive pinion 5 travelsalong the rod like a nut on a bolt.

The rod 6, mounted in bearings in the frame of the printer, is fixedrelative to one part ofa clutch 8' at one end and with one part of aclutch 9 and a brake 10 at the other end. The other part of clutch 8 isfixed relative to a drive which rotates at a speed faster than, and inthe same direction as, the typewheel drive pinion 5, and the other partof clutch 9 is fixed relative to a drive which rotates at the same speedand in the same direction of the typewheel drive pinion 5'.

The driving arrangement operates in the manner described below.

When no feed of the typewheel l is required in either direction, theclutch 9' is engaged and the rod 6' rotates with the typewheel drivepinion 5'. There is,

2 thus, no relative rotary motion between the rod 6' and the typewheeldrive pinion 5 and, therefore, no traversing motion. This may bevisualized as a bolt with a nut on it held still; the nut does nottravel along the bolt. When the typewheel l is to be fed forward, thatis in the direction of printing letters sequentially, clutch 9' isdisengaged and clutch 8' is engaged. The rod 6 then rotates faster thanthe typewheel drive pinion 5' and the hand of the helical groove is suchthat the typewheel l feeds forward to a new position whereupon clutch 8'is disengaged and clutch 9 reengaged. The feeding motion may bevisualized by the bolt with a nut on it being turned in the unscrewingdirection, the bolt not moving sideways and the nut being prevented fromrotating; the nut travels along the bolt in the screwing-off direction.

When carriage return is required, that is, the typewheel 1 must be fedto the beginning of a printing line,

both clutches are disengaged and the brake 10' is applied. The typewheeldrive pinion 5 now revolves rapidly with respect to the rod 6, andtravels rapidly along the rod 6' to the beginning of a line of print.This motion may be visualized by the bolt with a nut on it beingheld-stationary while the nut is revolved rapidly in the direction toscrew it on to the bolt.

To give some idea of the relative motions of the typewheel 1 and rod6,consider the typewheel drive pinion revolving at a speed of 1,200revolutions per minute, clutch 9' being driven at the same speed, clutch8 being driven at 1,236 revolutions per minute and the helical groovehaving four turns along the length of the rod 6'. Then during forwardfeed, the typewheel 1 moves forward one character pitch for eachcomplete revolution of the drive pinion, and during carriage return, thetypewheel l returns from the end of a line to the beginning in fourcomplete revolutions of the drive pinion 5' which correspond to the timetaken to print four characters. The dimensions of rod 6, typewheel l andtypewheel drive pinion 5 are, of course, chosen to suit a particularspeed of printing.

To prevent damage to the typewheel pinion 5 and rod 6, the helicalgroove is provided with a run-out at the line-start end so that thedrive pinion can revolve harmlessly without further sideways motion.Normally the clutching and braking operations arrest the traverse motionbefore the wheel reaches the run-out portion. A similar run-out isprovided at the other end as a further safeguard although the typewheel1' never approaches that end at a high traverse rate.

On-the-fly printing requires a hammer carriage which feeds insynchronism .with the typewheel. A simple method of doing this is shownhere where the hammer carriage llis linked to the typewheel assembly byvirtually inextensible cards 12 passing around pulleys 13' in the mannershown.

With a typewheel perpendicular to the one described hereinabove,obviously, it is the typewheel drive pinion only which can rotate aroundthe rod, rather than the typewheel itself.

In FIG. 1, gear 2 may be press fit or integral with a shaft 15 that isrotatably mounted through a frame stringer 16'. Shaft 15' is rotated bya motor 14'. A pinion 18 in mesh with gear 2 may have a shaft 19integral therewith or press fit thereinto and press fit into the leftend of pinion 3'. Shaft 19 is rotatable through stringer 16' as shown inFIG. 1. The carriage is illustrated at 25.

A fitting 22 is shown in FIG. 1 which has a head 23 and a shaft 24 whichmay -be integral therewith or press fit thereinto or therethrough. Shaft24' is press fit into the right end of pinion 3, but is rotatablethrough a frame stringer l7.-

Carriage 25' has a projection 21 into which a shaft 20 is press fit, asshown in FIGS. 1 and 3.

In FIG. 2, the manner in which shaft 'is rotatable through stringer 16'is illustrated. Shaft 15 has grooves 26 and 27 into which snap rings 28and 29, respectively, are fitted.

In FIG. 3, pinion 4 is maintained in a fixed axial position on androtatably around stub shaft For this purpose, stub shaft 20 has a snapring groove 30, and a snap ring 31 therein. The numbers 2, 3 and 4indicated by an arrow 32 in FIG. 3 are the same numbers 2, 3 and 4indicated by an arrow 32" in FIG. 1.

What is claimed is:

1. A printing mechanism comprising: a frame; a rod rotatably mounted onsaid frame parallel to a printing line, said rod having a cylindricalouter surface with a helical groove therein; a typewheel rotatable onsaid rod, said typewheel having a projection extending into said groove;first means mounted on said frame to cooperate with means mounted onsaid typewheel to rotat e said typewheel in a predetermined directioncontinously at a constant speed relative to said frame; second meansmounted on said frame, said second means being selectively operable torotate said rod in said predetermined direction at 'an angular velocitygreater than that of said typewheel; third means mounted on said frame,said third means being selectively operable to rotate said rod in saidpredetermined direction at an angular velocity equal to that of saidtypewheel whereby, when said third means is operable, no movement of thetypewheel along the rod occurs while when the second means is operablethe typewheel feeds to a new position; fourth means mounted on saidframe, said fourth means being selectively operable to brake said rodthereby causing said typewheel to be fed to the beginning of a new printline by said first means, said typewheel having type fonts mountedthereon therearound; and fifth means mounted on said frame, said fifthmeans being selectively operable to cause any one vof said type fonts tomake an impression on a recording medium.

2. The invention as defined in claim 1, wherein said first meansincludes a first pinion fixed to said typewheel, said rod and said firstpinion having the same rotational axis, a carriage slidable over saidrod in a fixed angular position therearound relative to said frame, saidtypewheel being rotatable relative to said carriage but always movabletherewith in the direction of said axis, a second pinion rotatablymounted on said carriage in mesh with said first pinion, a third pinionrotatably mounted on said frame in mesh with said second pinion, saidfirst and second pinions having thicknesses at leastan order ofmagnitude less than the thickness of said third pinion.

1. A printing mechanism comprising: a frame; a rod rotatably mounted onsaid frame parallel to a printing line, said rod having a cylindricalouter surface with a helical groove therein; a typewheel rotatable onsaid rod, said typewheel having a projection extending into said groove;first means mounted on said frame to cooperate with means mounted onsaid typewheel to rotate said typewheel in a predetermined directioncontinously at a constant speed relative to said frame; second meansmounted on said frame, said second means being selectively operable torotate said rod in said predetermined direction at an angular velocitygreater than that of said typewheel; third means mounted on said frame,said third means being selectively operable to rotate said rod in saidpredetermined direction at an angular velocity equal to that of saidtypewheel whereby, when said third means is operable, no movement of thetypewheel along the rod occurs while when the second means is operablethe typewheel feeds to a new position; fourth means mounted on saidframe, said fourth means being selectively operable to brake said rodthereby causing said typewheel to be fed to the beginning of a new printline by said first means, said typewheel having type fonts mountedthereon therearound; and fifth means mounted on said frame, said fifthmeans being selectively operable to cause any one of said type fonts tomake an impression on a recording medium.
 2. The invention as defined inclaim 1, wherein said first means includes a first pinion fixed to saidtypewheel, said rod and said first pinion having the same rotationalaxis, a carriage slidable over said rod in a fixed angular positiontherearound relative to said frame, said typewheel being rotatablerelative to said carriage but always movable therewith in the directionof said axis, a second pinion rotatably mounted on said carriage in meshwith said first pinion, a third pinion rotatably mounted on said framein mesh with said second pinion, said first and second pinions havingthicknesses at least an order of magnitude less than the thickness ofsaid third pinion.